1. Field of the Invention
This invention relates generally to lifting devices, and more particularly to an improved lifting stand assembly designed to lift and support heavy equipment, particularly during the installation or repair of furnaces, air conditioning units and the like.
2. Description of Related Art
Invention and use of lifting stand devices is known to the public, as they are frequently used to aid in a variety of lifting procedures. For example, Meyer U.S. Pat. No. 1,516,616 discloses a means for lifting a high placed object. As disclosed, the device includes a jacking means at a lower distal end and a support means at an upper distal end.
Reuter U.S. Pat. No. 3,017,174 discloses a jacking means which does not include a jacking device per se, but does include a work holder means at an upper distal end for holding and supporting a heavy object. Baron et al. U.S. Pat. No. 4,084,792 teaches a jacking device that includes a workpiece support attached to a vertical rod which may be telescopically jacked upward from a base structure. Van Santen U.S. Pat. No. 4,221,362 discloses a tall jack providing screw thread jacking means and a top mounted support plate. The device includes two telescopic square section tubes and narrow top and bottom plates are provided for the post, the plates being of a size for insertion within one of the tubes, and a cross pin is provided for insertion transversely through selected bores in the telescoped tubes.
Hobday U.S. Pat. No. 5,161,787 discloses an improved C-clamp that has a clamp body and a detachable setting mechanism. The clamp body has inner and outer legs with a hollow bore in the inner leg to allow passage of a stem having a work-engaging pad on its end therethrough toward an aligned fixed work pad on the outer leg. The setting mechanism for advancing the stem has a hand lever and hand grip that act in concert upon manual squeezing to step-by-step advance the stem. The setting mechanism removably attaches to the clamp body by a spring-biased lever that grips attachment pins on the body. A latch lever positioned on the inner leg of the clamp body causes a retaining lever to grip the stem when the latch lever is closed and to allow the stem to move freely when the latch lever is open.
However, all of these devices are significantly flawed in that they require relatively complex lifting assemblies, which makes them more expensive, more prone to extensive repairs, and more difficult to easily, properly operate. Thus, there is a clear need for an improved lifting stand that utilizes a relatively simple, inexpensive lifting device that is sturdy and reliable.
Chang U.S. Pat. No. 4,081,112 discloses a caulking gun assembly that provides means by which to easily move an elongate shaft through a housing unit with substantial force by means of a hand actuated trigger. This device has relatively few moving parts and is inexpensive to manufacture. However, as disclosed, the device is designed only for use as a caulking gun, and makes no provision for it to be used as a lifting device.
All of the prior art devices are significantly limited in that they have a relatively large size that is not conducive to use in limited space environments, such as those typically associated with furnace room installations. Thus, there is a clear need for an improved device that is as narrow and compact as possible. Such a device would be less expensive and more effective at lifting and supporting heavy objects than prior art devices. The present invention fulfills these needs and provides further related advantages as described in the following summary.